1. Technical Field of the Invention
The present invention relates to a mutual connection structure between a wire conductor and a terminal element, and particularly to a wire connection structure including an abutting member for abutting the wire conductor to the conductor-connecting section of the terminal element under pressure. Further, the present invention relates to a connector employing such a wire connection structure.
2. Prior Art
Two kinds of mutual connection structures between wire conductors and terminal elements have been known in the prior art; one being a so-called crimp fitting structure in which a wire conductor of a predetermined length exposed by removing a sheath from an end portion of the wire is connected to a conductor-connecting section of the terminal element by the plastic deformation (i.e., the caulking) of the latter, and the other being a so-called insulation-displacement structure in which a slit having a width smaller than a diameter of the wire conductor is provided in the conductor-connecting section of the terminal element to have a sharp profile, and the conductor-connecting section is pierced into the wire through the sheath thereof to press the conductor into the slit. These well-known wire connection structures have recently become unsatisfactory both in workability of the connecting operation and in processability of the terminal element, because the diameter of the wire conductor is smaller and the arrangement pitch of the terminal elements is narrower in correspondence to the recent demand for a high-density connection. As countermeasures for the high-density connection, various wire-connection structures are proposed, in which a wire conductor of a predetermined length exposed by removing a sheath from an end portion of the wire is brought into contact with a conductor-connecting section of a terminal element under a pressure (see, for example, Patent Document No. Japanese Unexamined Patent Publication (Kokai) No. 2000-277190 and Patent Document Japanese Unexamined Patent Publication (Kokai) No. 2000-306622).
According to the wire connection structure of the above conductor-abutting type disclosed in Patent Document No. Japanese Unexamined Patent Publication (Kokai) No. 2000-277190, a connector suitably applied to a multi-core type flat cable is proposed, comprising a plurality of terminal elements, each having a conductor-connecting section to be connected to the wire conductor, an electrically insulative body supporting the terminal elements while exposing the respective conductor-connecting sections therefrom, and a plurality of abutting members incorporated in the body to abut the individual wire conductors to the conductor-connecting sections of the terminal elements under a pressure. In this connector, the respective terminal element (a base contact) is provided with the conductor-connecting section having a curved edge, while the respective abutting member (a support contact) formed of a conductive metallic piece similar to the terminal element is provided with a curved contact surface in correspondence to the curved edge of the conductor-connecting section of the terminal element. The body supporting the terminal elements arranged at a predetermined pitch is assembled with an electrically insulative cover supporting the abutting members arranged at the corresponding pitch, while intervening the cable to be connected between the both, in the direction transverse to the cable-extending direction. Thus, the conductors in the cable are fixedly nipped under a pressure between the terminal elements and the abutting members corresponding thereto while being forcibly curved along the edge of the conductor-connecting section of the terminal element and the curved profile of the contact surface of the abutting member.
According to the wire connection structure of the above conductor-abutting type disclosed in Patent Document No. Japanese Unexamined Patent Publication (Kokai) No. 2000-306622, similar to the wire connection structure of Patent Document No. Japanese Unexamined Patent Publication (Kokai) No. 2000-277190, the conductor-connecting section having the curved edge is provided in the respective terminal element (a base contact), while the contact surface curved in correspondence thereto is provided in the respective abutting member. The body supporting the terminal elements arranged at a predetermined pitch is assembled with a pair of electrically insulative covers supporting the abutting members arranged at the corresponding pitch between the both, while nipping the cable to be connected between both the covers, in the direction parallel to the cable-extending direction. Thus, the conductors in the cable are fixedly nipped under a pressure between the terminal elements and the abutting members corresponding thereto while being forcibly curved along the edge of the conductor-connecting section of the terminal element and the curved profile of the contact surface of the abutting member.
The wire connection structure disclosed in the above-mentioned Patent Document Nos. Japanese Unexamined Patent Publication (Kokai) No. 2000-277190 and Japanese Unexamined Patent Publication (Kokai) No. 2000-306622 is adapted to nip the wire conductor between the edge of the conductor-connecting section of the terminal element and the abutment surface of the abutting member under a pressure generated due to the relative movement of the terminal element to the abutting member. Accordingly, since the wire conductor is rubbed by the metallic piece under a pressure, there is a risk in that the wire conductor may be damaged during the wire-connecting operation.
Also, a cable of semi-hard copper alloy conductor excellent in bending property is recently beginning to be employed in an electronic/information equipment having an open/close type display, such as a note type personal computer or a portable telephone, which cable is used for connecting the equipment body to the display while bridging over a hinge portion. The semi-hard conductor of such a kind exhibits a high-level durability against bending or twisting and is rich in shape-recovery property. Accordingly, if the wire-connecting structure disclosed in the above-mentioned Patent Document Nos. 2000-277190 and Japanese Unexamined Patent Publication (Kokai) No. 2000-306622 is applied to the cable of the semi-hard conductor of this kind, it is very difficult to dispose the cable conductor in advance along the curved edge of the conductor-connecting section of the terminal element or the curved abutment surface of the abutting member during the connecting operation, due to the shape-recovery property of the cable conductor. Thereby, the straightly extending cable conductor is gradually nipped between the curved edge of the conductor-connecting section of the terminal element and the curved abutment surface of the abutting member while being forcibly curved by the relative movement of the terminal element to the abutting member. In this operation, there is a risk in that the cable conductor is liable to deflect from a proper position relative to the terminal element and the abutting member during the forcible bending operation, and as a result, the stability and the reliability is lowered in the conductive contact between the cable conductor and the terminal element.
An object of the present invention is to provide a wire-connection structure ensuring the stability and the reliability in the conductive contact between the cable conductor and the terminal element even if the semi-hard conductor wire is used.
Another object of the present invention is to provide a connector of a high-density connection type in correspondence to the reduction of the diameter of the conductor wire and the arrangement pitch of the terminal element by employing such a wire-connection structure as excellent in the stability and the reliability.